nicholson



March 6, 1928.

1,661,546 H. A. NICHOLSON STEAM GENERATOR Filed Aug. 13. 1919 5 Sheets-Sheet 1.

jNVENTOR ATTORNEY March 6, 1926. 1,661,546

. H. A. NICHOLSON 6 STEAM GENERATOR Filed Aug. 15. 1919 5 Sheets-Sheet 2 INVENTOR ATTORNEY March 6, 1928. 1,661,546

H. A. NICHOLSON STEAM GENERATOR Filed Aug 13, 1919 5 Sheets-Sheet 5 INVENTOR zflmzY I V I ATTORNEY March 6, 1928. 6 1,661,546

H. A. NICHO LSON STEAM GENERATOR Filed Aug- 13. 1919 5 Sheets-Sheet 4 INVENTOR,

ATTORNEY March 6, 1928. I 1,661,546

H. A. NICHOLSON STEAM GENERATOR Filed Aug. 13. 1919 5- sheets-sneev. 5

. INVEN'LOR ATTORNEY ill) Patented Mar. 6, 1928.

UNITED STATES PATENT QFFICE.

HENRY A. NICHOLSON, OF- ARKLES BAY, AUCKLAND, NEW ZEALAND, ASSIGNOR TO ERNEST A. CRAIG, O33 AUCKLAND, NEW ZEALAND.

STEAM GENERATOR.

Application filed August 13, 1919. Serial No. 317,135.

This invention relates to steam generators of the class described in my co-pendmg application, No. 284,65, filed March 24, 1919, in which the water is forced bya pump to advance in a single direction through a course of piping which is subjected to the heat of a furnace; the water reaching a very hi h degree of temperature and pressure being finally converted into steam and retained in the steam drum ready for use. The piping is jacketed with a heat-conducting refractory material, which may reach a high degree of heat, and may become incandcscent, thus prolonging the life of the flames, which, in ordinary boilers, is found to become prematurely cooled and shortened by the relatively cool metal pipes. In said application the incandescent jackets impart heat to the pipes and the fluid therein, while said jackets remain highly heated at the portions thereof that are lapped by the flames, and hence the flames persist much longer, and combustion is made more complete, thus reducing or eliminating combustible carbon monoxide from the waste gases escaping from the furnace.

One of the objects of the present invention is to construct a simple and compact apparatus of the class described; to provide an improved flame chamber and flame passage, to extract a maximum of heating power from the fuel. Another object is to improve the construction of the flame chamber, which may be a chamber of the single combustion type. to secure increased efliciency; and the device may, if desired, operate as a gas producer, with provision being made for supplying air to mix with the carbon monoxide, to carry on secondary combustion. for heating certain of the water pipes in the system.

Another objectis to construct and dispose the pipe coils in a manner to conduce to simplicity and economy of manufacture and accessibility of the piping, for inspection and cleaning.

In carrying out the present improvements, the fire chamber is placed at the center of the generator, and comprises a front wall, a rear wall and side walls. In each side wall is a coil of piping, forming part of the course through which the water is forced by the pump. The flames divide and pass over the tops of these side walls, and down through passages was? a alls; the latter being thus heated on both sides, and the piping therein being hence subjected to OX- treme heat. The coils in these walls preferably constitute the final portion of the fluid course, and lead directly to the steam drum at the end of the system.

The flames flow down said passages into flame chambers near the bottom of the apparatus, and thence rise between partitions which consist of heat-conducting refractory material, in each of which is imbedded a grid or coil of relatively fine pipin These grids form part of said water course or system. Waste gases escape from the tops of said passages between. the partitions, passing up fines to the stack.

The steam-drum referred to may be placed at the central portion of the generator, above the fire chamber, where it will be superheated. Said steam-drum may be flanked by water drums in which is contained a reserve of water at the intake end of the generator; the pump forcing the water first into said water drums and thence through distributing headers into said grid sections, from which the fluid is collected by headers leading to the described coils in the side walls of the fire chamber, where the fluid receives its final access of heat before being delivered to the steam-drum.

Each coil is made up of lengths of piping, which are connected at their ends in a manner to give a zigzag course to the coil; screw plugs being provided in the front wall of the furnace for all of the coils in the generator.

Included in the apparatus set forth in said application is a reserve water drum, used for l eating or maintaining the heat of the water as it advances through the system in which said reserve water drum is included); the water in this drum being also available to enable the genrator to keep on developing steam when the pump is temporarily shut down, or when for any other reason, there is an. obstacle to the regular flow of water through the system.

In said application, the water reserve drum and steam-dru1n are connected by means of a tube or bypass, in which is fitted a valve which is normally closed during the regular operation of the steam-geenrator, but which may be opened by the attendant whenever the pump is stopped, or whenever the pump is not working, as

any other occasion demands. This valve is also intended to be closed by the attendant when the pump is started again.

One of the objects of the present improvei'nents is to avoid the necessity of having this by-pass-\'al\-'e opened and closed by the attendant, who might iorpgct or .ilcglect to attend to the opening at the valve in emergency, thereby rendering the generator liable to collapse for lack of circulation of water therein.

According to the present improvements, the, by-pass-valve is automatically controlled, being arranged to stand open when for example, when the generator is being warmed up. Upon startingthe pump, the valve in the bypass is automatically closed. Upon cessation oil the operation oi the pump, said valve aiit()niatical.ly opens, so that safety of the generator is ircd.

The two drums aforesaid are connected by a cross main, whichis normally closed; but provision is made whereby at the closing down of the pump, said cross main or by-pass is automatically opened, thus conjl lec ting the water drums to each other and to the steam drum, thus permitting circulation to be set up by reason of the action of heat upon the water contained in the syst'eni.

Other features and advantages will hcreina ltcr appear.

In the accompanying drawings, Figure 1 is. a diagrammatic front elevation oi a generator en'ibodying the present improvements in one form.

Figure 2 is a part-sectional front elevation. of the apparatus.

Figure 8 is a part-sectional side elevation.

Figure 4; is a diagran'nnatic plan of the water and steam drums, showing in section the valve mechanismtor automatically controlling the direct connection between said drums; the valve being shown closed.

Figure 5 is a detail to show the valve open which is clo'-ed at Figure s.

Figure 6 a part-sectional plan of the apparatus.

Figure '4" is a diagrammatic sectional detail of a throttle valve for the pump which feeds the generator; illustrating the means for automatically exhausting the steam from the steam chest of the pump when the pump is closed down.

7 Figure 8 is a diagrannnatic side elevation of the pump, with its steam chest, a steam pipe feeding to said chest, :1 w: rte or exhaust pipe for said chest, a pipe leading from said chest to hold the valve closed Figure i, and a water delivery pipe which extends from said pump to the generator.

Water is supplied by a steam-driven force 3 20, through a main. 21,; which has branch mains 2 2, 23 to feed the water drums 2e, 25, placed at thetop of the generator, which comprises a front wall 26, a rear wall 27, and side walls 28, 29. From the "front ends of said water drums extend headers 30, 31. extending towards thesidc wallsot the Li'urnace, each header being used for distributing water to sections :32 forming; grids. Each grid section comprises a coil imbed- (led in refractory heat-conducting material 'lforining' a partition 3;). Upward passages for the flames are formed by the partitions, said passages opening into common fines leading to'a stack 36. Each of those grid sections comprises a serics of horizontal pipesB'Y, placed one above another, the pipes being connected at their ends by U-fittings or unions 38-, in a manner to form a single zigzag course; and in the tront'wall of the boiler may be arranged screw plugs 39, for all the pipes in each. grid section. Said front and rear walls 27, may be made of retlfractory material; the front and rear ends of the zigzag turns being imbedded in said walls. It desired, the pipes may be arranged in pairs, each pair formed with a bend at its rear end, as seen at Figure 3, and the front ends ot the tubes may be arranged with Uslitti having the plugs 89 aforel '1 l '41- said. These watei coils are sepaiateo, wna the flame chamber between them; and the water advances from the portion of the furnace which is remote from the grate 52 and re atively cool, to the portion which is near said grate and relatively hot-.f

At their lower ends, the sections in the grids open individually into collecting headers ll) which. lead to the lower ends of main coils ll. These main coils, like the grid coils, stand upright within the generator. and, like the grid coils, are formed of lengths 42 of piping connected by fittings 43 at their rear ends and by U-fittings l l at their trout ends to form zigzag; coils; the upper ends of these coils delivering by means of pipes 45 to the front end of a steam-drum -16, placed at the central upper portion of the apparatus. The water receives the main portion or" its heat while it is in the coils. As set forth in said application, there may he provided in the steamdruni a pressure-reducer 47, into which both of the pipes may (.oliver, and whcrcl' the remainder of the water in. the fluid co vcrtcd into steam. The fluid up to this eta has been subjected "for a considerable period to. exceedingly high heat and pressure oi? say 300. poundsv or more pcr sq'uare' inch and at this point itissues into the drum 46 as steam and is retained atv a somewhat lmvcr pressure in said drum, from which extends a service pipe L8.

Said final heating coils l2 are imbedded in chamber 50, extending from the front wall to the rear Wall ofthe furnace; the rear and front walls at the flame chamber being preferably thickened at 51, as illustrated at Figure 3. At the bottom ofthe fire-box may be arranged a grate 52, to which access may be had through a door 53; the lower door 54 at Figure 2 opening into an ash pit 55.

The flames which rise from the fuel in the fire-box pass up to the top of the fire chamber, and then divide and pass down through outer passages 56 alongside of said fire-box walls 49, so that an increased heat is imparted to the fluid as it is forced up through the main coils tl to the steam-drum. Said passages 56 lead the flames down at each side to lower horizontal flues 57, at the sides of the generator, and from these lines the flames subdivide and rise through outlets 58 to the relatively small passages Set between the partitions 33 in which are in1 bedded the grid sections or coils. These passages 3etlead at each side to the passage or flue 35 communicating with the stack 36. The inner walls of the flues and the lower portions 01' the stack may form an arch, so that flames cannot pass up around the drums and escape directly into the stack, but must be diverted into the outer passages and eventually rise through the narrow passages and the fines to the stack.

lVhen it is desired to use thefire-box apparatus as a gas producer, air may be supplied through conduits 59 extending from front to rear at the lower portion of the side walls 49 of the fire-box, and having openings 60 into the latter. The air may be forced by a blower 61 through a. pipe 62. The carbon monoxide from the fire-boX passes over the tops of the side walls 49 and down through the passages 56 into the main passages 57 of the lower part of the apparatus; a secondary air-supply conduit 63 being provided for each of said main passages 57, being connected by passages 63 to supply the air nec-essary for the combustion of the carbon monoxide. The flames from this combustion pass through the narrow upward passages 34, thereby heating the fluid, and finally escape through the dues to the stack. The air-supply pipe 62 may have an elbow 64 to supply air below the grate. Said pipe 62 may cross over the fire door, and open into U-pipes- 65 which supply the passages 59 and 63. Fuel may be introduced through the upper door 65 seen at the front of the furnace.

For the purpose of temporarily providing a circulation in the steaming system in case it should become necessary to close down the force pump 20, there is provided a by-pass or direct connection between the three drums, whichconnection is closed during the ordinary steaming operation. This. connection comprisesa cross main 66 extending from one water drum Ql'to the other having at its ends elbows to connect with the ends of said drums, and having at its middle portion a short pipe or fitting 67 to connect it to the end of the steam-drum 4.6, which is located between the water-drums. This connect-ion enters end or the steam-drun'i at its lower part, and enters the ends of the water-drums at their upper portions, thereby conducing to eti'ective circulation when required. Normally this cross main 66 is entirely closed, so that no direct communication occurs between the water-drums or from the steam-drum to the water-drums. This closing may be effected by any suit able means, and, desired, may be under the control of an attendant. However, the opening and closing of this communication between the drums is preferably automatic, and preferably comprises a slide valve 68 which is movable endwise in the cylinder or fitting 67 which connects said cross main to the steamdrum. This valve fits closely in said cylinder, and therefore closes the passage through the main 66 from water-drum to water-drum, so that no water can circulate between said water-drums. At the same time the valve closes the passage between the steam-drum and said cross main, which passage consists of said cylinder or cylindricalfitting, thus entirely closing direct communication. Said valve, which is movable endwise in said cylinder, that is, in the direction of the length of the steam-drum, is held closed by means of steam pressure acting upon a piston 69, which is of greater diameter than the valve 68,-and tits in an enlarged cylinder '70, and is connected with said. valve 68 or forms a continuation thereof. The large cylinder 70 is supplied with steam through a pipe 71, which enters the head of the cylinder and leads from the steam chest 72 of the force pump 20. So long as the pump is in operation, the pressure of steam delivered through said pipe 71 to said cylinderpresses against the piston 69, and holds the valve in closed position at Figure 4" The steam in the steam-drum tends constantly to force said valve 68 in the opposite direction, but the piston 69 is of greater diameter than the valve, and hence the pressure of steam from the pump chest against the piston overbalances the pressure of steam from the drum in pressing in the opposite direction against the valve, so that the latter is kept closed. lVhen, however, the engineer, by turning a hand-wheel 73, closes a throttle valve T l in the steam pipe 75 that supplies the pump, the stem 76 of said valve. in moving endwisc. is arranged to exhaust the steam from the steam chest 72 of the force pump; and hence the pressure in the cylinder 70 is reduced so that the piston 69 can no longer retain the valve 68 closed; but the direct pressure of steam from the steam-drum acts upon said valve, and

pushes the same out to the position at Figure 5,and ports 77 in said valve come into communication with the opposite portions of the cross main (56 between the waterdrums, thereby establishing direct communication between said drums. hi'oreover, the valve 68 is hollow, so that a passage is also opened between the steam-drum a6 and both of the water-drums, as will be understood from Figure Thus communication is automatically established between the three drums whenever the pump is shut down, and since the water drums are in open communication with the side tubes and the steam drum with the inner tubes any abnormal pressure at any part of thesystem can be transmitted through the drums and tubes to relieve the localized pressure and danger oi injury to the pipes or drums through the hirn'iing of stationary steam bubbles during the closing down of the pump is thus avoided. I r

The device which automatically exhausts the steam "from the steam chest of the force pinup comprises the stem 76 of the throttle valve 7%, and a cylindrical valve 78 which is carried upon the inner end of said stemyand has a peripheral groove 79 forming a steam passage, which groove is normally closed by the walls or the cylinder 80 in which said valve works. Said cylinder 80 extends from one side of the valve casing 81 in the steam supply pipe 75. When said throttle valve 7 4; is closed, the valve 78 is displaced far enough to bring the groove 79 therein into com munication with ports 82 provided in the sides of said cylinder 80 thereby opening an exhaust or waste pipe 81 which leads from said steam chest 72, as at Figure 7, so that steam is exhausted from said chest, and hence pressure is reduced in the pipe 71 and in the cylinder 70 in which works the piston (39, so that, owing to theunbalanced condition of the valve 68, the steam from the steam-drum is enabled to force the same to open. Upon opening the throttle valve 74: and starting the pump 20, the valve 7 8 is moved so far to the right, from Figure 7, as to bring the groove 79 therein. out of register with the ports 82 in the cylinder, thus closing the exhaust pipe 81, so that steam is maintained at working pressure in the chest 72 of the pump, and hence steam pressure rises again in the pipe 71 which leads from the chest to the cylinder 70 at the end of the steam-drum, and the pressure from the oversiz ed piston 69 onsaid cylinder forces the valve to position shown at Figure 4, thereby again closing direct communication among the three drums. V Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

rming thus described my "invention, I

claim 2 gle direction through said coils to said steam? drum; provision being madeat the ter'n'iinal end of the piping system tor convertingan y ren'iainingwater of the high heated high pressure pent up advancing fluid into steam.

2. A steam-generator having an interior flannr-chan'iber, the latter comprising front, rear and side walls, a system of piping including coils ins-aid side walls and also including additional coils, a steam-drumxto which said side-wall coils deliver, and

pump to force fluid through said additional coils 1nd then through said side-wall coils to said steam-drum, means "for reserving fluid being included between said pump and said additional coils.

3. A steam-generator havin'gan interior i'laine-cnamber, the latter comprising front,

rear an d side walls,each side wall containing a coil of piping, said coils together with ad ditional coils forming a fluid-pipe system a pump to force fluid under high pressure only once in a single'direction through said system, a nda steam-drum at the delivery endqojf said fluid-pipesystem, flame-passages being provided over-the top and down along side of said side walls, so that the. latter are heated on both sides, and so that the 'tlai'nes and hot may have access to said additional coils, provision being made at the terminal end ot the piping system for converting any remaining water of the'highheated high pressure pent up advancing fluid into steam.

l. A- steam generator having an interior flame-chamber, the latter comprising front, rear and side walls, eachsidewall containing a coil of piping, saidvcoils together with additional coils forming a pipe system, apump to iorcevfluid underhigh pressure only once in a single direction through said system, and

a steanrdrum at the delivery end of said pipe system, flame passages being provided over the top and down alongside of'said side walls, so that the latter are heated onboth sides, and so that the'fi'ames and 1 0i; gases may have access to said additional. coils and provision being made at the terminal end'o't 7 system for converting any the piping ma 11mg water. oft-the. highly heated liifghpressure pent-up advancing flu d into steam;

the coils in saidwallsconstitutingthe te'rminal po'rtioii of the piping system. e 5. A steamagenerator comprising, a'fianie chamberih'avin'g front; rear and sidewalls, coils imbedded insaid-side Walls, partitions to form pa'ssages.;tor.;the flames gutside of said side walls, coji'ls ot-piping imbedded in Ill) said partitions and connected at their delivery ends to the coils incsaid side Walls, water-reserve drums delivering to said partition coils, a steam-drum collecting from said side wallcoils, and a force pump to advance fluid through said water-druins and said coils to said steam-drum. a

6. A steam-generator comprising a flame chamber having front, rear and side walls, coils imbedded in said side walls, partitions to form passages for the flames outside of said side walls, coils of piping imbedded in said partitions and connected at their delivery ends to the coils in said side walls, waterreserve drums delivering to said partition coils, a steam-drum collecting from said side wall coils, and a force pump to advance fluid through said water drums and said coils to said steam-drum, passages being provided over the tops of said side walls and beneath said partitions, and escape flues leading from said partitions.

7. A steam-generator comprising a flame chamber having front, rear and side walls, coils imbedded in said side walls, partitions to form passages for the flames outside of said side walls, coils of piping imbedded in said partitions and connected at their delivery ends to the coils in said side walls, wa reserve drums delivering to said partition coils, a steanrdrum collecting from said side wall coils, and a force pump to advance fluid through said water-drums and said coils to said steam-drum, said steam-drum being placed above said flame chamber or fire-box, and said water-drums being placed at the sides of said steam-drum above said partitions.

8. A steam-generator comprising a flame chamber having front, rear and side walls, coils imbedded in said side walls, partitions to form passages for the flames outside of said side walls, coils of piping imbedded in said partitions and connected at their delivery ends to the coils in said side walls, waterreserve drums delivering to said partition coils, a stean1-dru1n collecting from said side wall coils, a force pump to advance fluid through said water-drums and said coils to said steam-drum, distributing headers extending from said water-drums to the coils in said partitions, and collecting head-- ers leading from said partition coils to the coils in said side walls.

9. A steam-generator comprising a flame chamber having front, rear and side walls, coils imbedded in said side walls, partitions to form passages for the flames outside of said side walls, coils of piping imbedded in said partitions and connected at their delivery ends to the coils in said side walls, water-reserve drums delivering to said partition coils, a steam-drum collecting from said side wall coils, and a force pump to advance fluid through said water-drums and said coils to said steam drum, the piping in all of said coils extending into the front wall of the furnace, and plugs being provided at the front wall for all of said pipin in said partitions, a water-reserve meansconnected to the intake ends of said coils, and. a pump to force fluid to advance through said coils to said drum.

ll. A steam-generator having front, rear andside walls and containing a central flame chamber having side walls, with passages for the flames over the tops of the lastmentioned side walls, coils imbedded in said side walls, partitions between the side walls of the flame chamber and the side walls of the furnace, passages being provided below said partitions, coils of fluid piping imbedded in said partitions, a steam-drum to which the fluid advances through the coils in said partitions and in the side walls of said flame chamber, a water-reserve means connected to the intake ends of said partition coils, a pump to force fluid to advance through all said coils to said drum, distributing headers between said water-reserve means and said partition coils, and collecting headers connected to said partition coils and to said steam-drum.

12. A steam-generator having front, rear and side walls with coils therein and con taining a central flame chamber having side walls, with passages for the flames over the tops of the last-mentionedside walls, partitions between the side walls of the flame chamber and the side walls of the furnace, passages being provided below said partitions, coils of fluid piping imbedded in said partitions, a steam-drum to which the fluid advances through the coils in said parti tions, a water reserve means connected to the intake ends of said coils, and a pump. to force fluid to advance through said coils to said drum, said water reserve means comprising a pair of drums at the sides of said steam-drum, the latter being arranged over the flame chamber.

13. A steam-generator having front, rear and side walls and containing a central flame chamber having side walls, with passages for the flames over the tops of the last-mentioned side walls, partitions between the side walls of the flame chamber and the side walls of the furnace, passages being provided below said partitions, coils of piping imbedded in said partitions, a Water reserve means connected to the intake ends of said coils, distributing headers between said wa ter reserve means and said coils, collecting headers connected to said coils, coils iinbedded in the side Walls of said flame chamber and connected to said collecting headers, a steam-drum to which the last-mentioned coils are also connected.

M. A steam-generator comprising a steamdrum, a force pump, a system of piping through which Water is forced only once in a single direction by said pump, a 'Waterreserve drum being includedin said system, a flame-chamber arranged Within said generator and having a side Wall, a coil ineluded in said system and imbedded in the side wall of said flamehhamber and connected to deliver to said steam-drum, a second coil also included in said system and exter io-r to said side wall and Within the generator and connected to receive fluid from saidwvater reserve drum and deliver it to the first coi1,-a flarne passag=e being arranged at the top of said Wall, to permit the flames to flow over and descend by the side of said Wall, and a partition in which the second coil is imbedded, a passage being left at-the bottom of said partition, so that thedesoending flames and gases may rise on the other side of said partition; and provision being made at the terminal end of the pipingrsystein for converting any remaining Water of the highly heated high-pressure pent-up advancing fluid into steam.

15 A steam generator having an internal also included in said system and embeddedin said side walls to receive fluidf rom the first mentioned coils,.and a steam drum, provision being made at the terminal end of the piping system for converting remaining water of the highly heated high-pressure pent-up advancing fluid into steam.

HENRY A. nioiionson. 

